958120162016eng64516457postprint1--2016-02-10--How imperfect mixing and differential diffusion accelerate the rate of nonlinear reactions in microfluidic channelsIn this paper, we show experimentally that inside a microfluidic device, where the reactants are segregated, the reaction rate of an autocatalytic clock reaction is accelerated in comparison to the case where all the reactants are well mixed. We also find that, when mixing is enhanced inside the microfluidic device by introducing obstacles into the flow, the clock reaction becomes slower in comparison to the device where mixing is less efficient. Based on numerical simulations, we show that this effect can be explained by the interplay of nonlinear reaction kinetics (cubic autocatalysis) and differential diffusion, where the autocatalytic species diffuses slower than the substrate.urn:nbn:de:kobv:517-opus4-95810online registrationAu-032779Phys.Chem.Chem.Phys. (2016) Nr. 18, S. 6451-6457. - DOI: 10.1039/c6cp00224b<a href="http://publishup.uni-potsdam.de/opus4-ubp/frontdoor/index/index/docId/9580">Bibliographieeintrag der Originalveröffentlichung/Quelle</a>Robert NiedlIgal BerensteinCarsten BetaPostprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe253enguncontrolledarsenious acidenguncontrolledfrontsenguncontrolledpaperenguncontrolledpoly(dimethylsiloxane)enguncontrolledscaleenguncontrolledsystemsChemie und zugeordnete Wissenschaftenopen_accessInstitut für ChemieReferiertOpen AccessUniversität Potsdamhttps://publishup.uni-potsdam.de/files/9581/pmnr_253_online.pdf958020162016eng6451645718articleRoyal Society of ChemistryCambridge1--2016-02-10--How imperfect mixing and differential diffusion accelerate the rate of nonlinear reactions in microfluidic channelsIn this paper, we show experimentally that inside a microfluidic device, where the reactants are segregated, the reaction rate of an autocatalytic clock reaction is accelerated in comparison to the case where all the reactants are well mixed. We also find that, when mixing is enhanced inside the microfluidic device by introducing obstacles into the flow, the clock reaction becomes slower in comparison to the device where mixing is less efficient. Based on numerical simulations, we show that this effect can be explained by the interplay of nonlinear reaction kinetics (cubic autocatalysis) and differential diffusion, where the autocatalytic species diffuses slower than the substrate.Physical chemistry, chemical physics : PCCP ; a journal of European Chemical Societies10.1039/c6cp00224b1463-9076 (print)1463-9084 (online)online registrationAu-032779<a href="http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-95810">Zweitveröffentlichung in der Schriftenreihe Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe ; 253</a>Robert NiedlIgal BerensteinCarsten Betaenguncontrolledarsenious acidenguncontrolledsystemsenguncontrolledpoly(dimethylsiloxane)enguncontrolledfrontsenguncontrolledscaleenguncontrolledpaperChemie und zugeordnete WissenschaftenInstitut für ChemieReferiertOpen AccessRSCUniversität Potsdam4485520162016eng394otherAmerican Physical SocietyCollege Park1------Comment on "Flow-induced arrest of spatiotemporal chaos and transition to a stationary pattern in the Gray-Scott model"In this Comment, we review the results of pattern formation in a reaction-diffusion-advection system following the kinetics of the Gray-Scott model. A recent paper by Das [Phys. Rev. E 92, 052914 (2015)] shows that spatiotemporal chaos of the intermittency type can disappear as the advective flow is increased. This study, however, refers to a single point in the space of kinetic parameters of the original Gray-Scott model. Here we show that the wealth of patterns increases substantially as some of these parameters are changed. In addition to spatiotemporal intermittency, defect-mediated turbulence can also be found. In all cases, however, the chaotic behavior is seen to disappear as the advective flow is increased, following a scenario similar to what was reported in our earlier work [I. Berenstein and C. Beta, Phys. Rev. E 86, 056205 (2012)] as well as by Das. We also point out that a similar phenomenon can be found in other reaction-diffusion-advection models, such as the Oregonator model for the Belousov-Zhabotinsky reaction under flow conditions.Physical review : E, Statistical, nonlinear and soft matter physics10.1103/PhysRevE.94.046201278415332470-00452470-0053wos2016:2019046201WOS:000385247500004Berenstein, I (reprint author), Univ Libre Bruxelles, NonLinear Phys Chem Unit, Campus Plaine,Case Postale 231, B-1050 Brussels, Belgium.; Berenstein, I (reprint author), Univ Libre Bruxelles, Interdisciplinary Ctr Nonlinear Phenomena & Compl, Campus Plaine,Case Postale 231, B-1050 Brussels, Belgium.importub2020-03-22T13:40:01+00:00filename=package.tar61fe65fdd5067852c6c8f76001d04e78Igal BerensteinCarsten BetaYannick De DeckerInstitut für Physik und AstronomieReferiertImport